Edge boards and related assemblies

ABSTRACT

An assembly comprises a supporting substructure and at least one longitudinally extending board member supported on the substructure. An edge member is mounted proximate an end portion of the board member and has a lower portion configured for attachment to the substructure, and an upstanding wall portion extending from the lower portion. The upper wall portion defines an open channel and provides an opening into the open channel. The edge member is attached to the substructure and the end portion of the board member is received through the opening of the edge member into the open channel. The channel can accommodate longitudinal expansion and contraction of the board member. The board member may be made of a natural fiber thermoplastic material. The assembly may be configured as a deck assembly.

FIELD OF THE INVENTION

The present invention relates generally to edge boards used at the ends of board members employed in construction structures such as for example, decking, flooring and siding assemblies.

BACKGROUND OF THE INVENTION

Construction structures often involve the use of long board members, which are affixed in longitudinal, parallel alignment with each other. For example, decking or other types of flooring assemblies typically include horizontal floorboards/deck boards supported on a substructure. For decking assemblies, the deck boards and usually the supporting substructure are supported above ground level, often with the assistance of structural support posts.

Decking assemblies are often formed from a substructure formed with interconnected joists and headers. Several board members of lumber or other material are then typically transversely fixed across the joists of the sub-frame, in a generally parallel relationship, by way of nails driven through the top surface of the boards.

These decking assemblies, while being adequate for most general purposes, exhibit several shortcomings. These include compromised structural integrity, difficulty in assembly, and limited aesthetic appeal. The use of nails with wooden boards in conventional decking assemblies exhibits each of these problems.

Alternative ways of constructing decking assemblies which have been proposed, include the use of a nailing anchor to fix boards to a sub-structure from their bottom surface. Examples of such decking assemblies are disclosed in U.S. Pat. No. 4,620,403 to Field; U.S. Pat. No. 5,775,048 to Orchard; U.S. Pat. No. 4,965,980 to Leavens; and in Canadian Patent number 2,015,733 to Commins. While the use of a nailing anchor may address aesthetic concerns, such assemblies are typically time-consuming to assemble. Moreover, they do not address any of the more important structural concerns arising from the use of nails in a wooden structure.

Equally as significant, the use of nails or other fasteners driven into wood boards makes disassembly and repairs of decking assemblies difficult. Moreover, disassembled boards typically include nail markings and holes from previous assembly, and are not easily re-used.

To avoid some of the shortcomings of wooden boards, the use of polymer/plastic boards has been proposed. Polymer boards do not rot or decay like wooden boards. However, unlike wood, plastic and polymer boards quite susceptible to variations in temperatures, particularly with respect to changes in physical dimensions.

More recently deck boards made from composite materials, particularly those classified as reinforced fiber plastic composites (RFP composites), and natural fiber, thermoplastic composite (NFTPC) materials have been used. The latter class can use a mix of a thermoplastic resin and one or more natural fiber materials. The natural fibers that have been employed include but are not limited to natural wood fiber, wood flour, shell fiber, flax fibers, rice hulks and other agricultural fibers. Various types of thermoplastic resins can also be employed in the composites including but not limited to polyethylene, polypropylene, polyvinyl chloride and engineering thermoplastics.

However, deck boards made from materials such as plastic or NFTPC materials, and which are usually exposed directly to changes in the outside environment, particularly changes in temperature, have shortcomings in deployment resulting from the thermal expansion and contraction of the deck board members. This is particularly the case, where deck boards of relatively large lengths are required. For example, a deck board made from a mixture of materials such as natural wood fibers and a binding thermoplastic resin such as polypropylene, has a coefficient of thermal expansion that may be in the range of about 1-5 m/m/degrees celsius×10 minus 5. Thus, a deck board that is 7 meters (700 cm) long will, during a temperature change from 30 degrees celsius in summer to minus 20 degrees celsius in winter, may experience a change in length of in the range of about 0.35 to 1.75 cm in length.

Aside from thermal expansion, some materials can significantly expand in dimensions, particularly longitudinally, when certain other conditions are changed. For example, increased moisture in the environment can lead to increased moisture content in some materials. This in turn can lead to an increase in the dimensions of the board members.

Such dimensional instability may be a particular problem at the end of the boards at the end or side of a decking area. The result on a deck may be boards which protrude beyond the desired edge plane of the deck in summer and/or boards which provide gaps either at the ends, or between consecutive boards in winter.

Other types of non-plastic, and non-plastic composite boards, are also capable of significant expansion, particularly in the longitudinal direction.

Accordingly, an improved system that addresses some of the existing shortcomings of using plastic and members in known decking assemblies and other construction applications is desirable.

SUMMARY OF THE INVENTION

According to one aspect of the invention there is provided an edge member comprising an enclosed lower channel defined by lower channel wall portions; an upstanding wall portion extending from the lower channel wall portions, the upper wall portion defining an open channel and providing an opening into the open channel.

According to another aspect of the invention there is provided an assembly comprising a supporting substructure; at least one longitudinally extending board member supported on the substructure, the board member having an end portion; an edge member mounted proximate the end portion of the board member, the edge member comprising: a lower portion configured for attachment to the substructure; an upstanding wall portion extending from the lower portion, the upper wall portion defining an open channel and providing an opening into the open channel; the edge member being attached to the substructure and the end portion of the board member being received through the opening of the edge member into the open channel, wherein the channel can accommodate longitudinal expansion and contraction of the board member such that the end portion remains substantially within the open channel of the edge member.

According to another aspect of the invention there is provided an assembly comprising: a supporting substructure; first and second longitudinally extending board members supported on the substructure, the first and second board members each having an end portion; first and second edge members mounted in back to back relation to each other, the first edge member also mounted proximate the end portion of the first board member, the second edge member also mounted proximate the end portion of the second board member, the first and second edge members each comprising: a lower portion configured for attachment to the substructure; an upstanding wall portion extending from the lower portion, the upper wall portion defining an open channel and providing an opening into the open channel; the first and second edge members being attached to the substructure, and the end portion of the first board being received through the opening of the edge member into the open channel, the end portion of the second board member being received through the opening of the second edge member into the open channel, wherein the channels can accommodate longitudinal expansion and contraction of the first and second board members such that the end portions remains substantially in the open channels of the edge members.

Other aspects and features of the present invention will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

In figures, which illustrate, by way of example only, embodiments of the present invention,

FIG. 1 is a perspective view of a known decking assembly, with parts broken away showing a substructure;

FIG. 2 is a perspective view of a first embodiment of a known board that may be used to form the decking assembly of FIG. 1;

FIG. 3A is a perspective view showing an example of a hold-down clip forming part of the decking assembly of FIG. 1, and exemplary of an embodiment of the present invention;

FIG. 3B is a transverse cross-sectional view of the hold-down clip of FIG. 3A;

FIG. 3C is a longitudinal cross-sectional view of the hold-down clip of FIG. 3A;

FIG. 4A is a perspective view of two boards of FIG. 2 in side-by-side relation to each other, with a hold-down clip of FIG. 3A in place prior to being fixed to a joist;

FIG. 4B is a perspective view of two boards of FIG. 2 in side-by-side relation to each other with a hold-down clip of FIG. 3A in place after being fixed to a joist;

FIG. 5 is a perspective front view of an edge board member;

FIG. 6 is a right side elevation view of the edge board member of FIG. 5, the left side elevation view being a mirror image;

FIG. 7 is a bottom plan view of the edge board member of FIG. 5;

FIG. 8 is a front elevation view of the edge board member of FIG. 5;

FIG. 9 is a top plan view of the edge board member of FIG. 5;

FIG. 10 is a left side elevation view of the edge board member of FIG. 5;

FIG. 11 is a rear elevation view of the edge board member of FIG. 5;

FIG. 12 is a side elevation view of the edge board member of FIGS. 5-11 shown employed in part of a decking assembly;

FIG. 13 is a perspective view of a decking assembly employing several of the edge board members of FIGS. 5-11;

FIG. 14 is a perspective view similar to FIG. 13, of a similar decking assembly employing several of the edge board members of FIGS. 5-11; and

FIG. 15 is a cross sectional view at 15-15 in FIG. 14.

DETAILED DESCRIPTION

FIG. 1 illustrates a known decking assembly 10 that may for example be used as a residential patio deck, a boardwalk, a boat dock, stairs, a bench or a bridge. Other uses will be apparent to those of ordinary skill in the art.

Decking assembly 10 preferably includes a substructure 11 including headers 12 placed around a plurality of joists 14 spaced evenly apart at a preferred distance of approximately 16 inches on center, and in a parallel relationship to one another. Headers 12 and joists 14 may be made of any decking supporting material, including but not limited to untreated and treated solid wood and metals including steel and aluminum.

Transversely placed upon the joists 14 are a plurality of boards 16 spaced evenly apart in parallel relationship to one another and held down on the substructure 11 by way of hold down clips 24. It will be appreciated that while deck assembly 10 is shown with only one board 16 spanning the end joists 14 a, 14 b, a plurality of boards could be employed in end-to-end longitudinally aligned relation to provide for a larger separation between the outermost joists 14 a, 14 b.

FIG. 2 illustrates an example board 16, used to form the decking assembly 10, of FIG. 1. Board 16 may be instead formed of plastic/polymer, or from a composite such as NFTPC. Such boards 16 may be formed by combining wood particles/fibers or from a natural agro-fiber such as rice hulks, with a suitable thermoplastic resin. Suitable plastics that can be employed include but are not limited to polyvinyl chloride (PVC), polyolefins (polyethylene, polypropylene) and engineered plastics such as ABS, acrylic and polycarbonate. The wood fibers and resin may first be mixed together and then heated in an appropriate device. Alternatively the wood fiber and resin mixture can be pelletized and then stored for use in the future when they can be heated in an appropriate device. Possibly other additives such as pigments, lubricants, coupling agents and UV stabilizers, might also be incorporated. The heated mixture is typically extruded or pultruded through a suitably configured mold or die. Examples of suitable processes are disclosed in US patent publication no. 2005/0031724 A1 filed under Ser. No. 10/635,851 by Pabedinskas, the contents of which are hereby incorporated herein by reference. Boards can also be formed by known injection molding systems and methods.

A possible shaped board that can be formed by such a process, is board 16 shown in FIG. 2. Board 16 contains a multitude of generally vertical webs or ribs 20 extending lengthwise along each board 16 between two substantially flat side web portions 22 a and 22 b, and having a generally uniform cross-section throughout its length, as for example, detailed in U.S. Pat. No. 5,234,652, the contents of which are hereby incorporated herein by reference. Ribs 20 can be equally spaced apart and define rectangular shaped, longitudinally extending chambers 21, extending parallel to one another between flat side portions 22 a and 22 b along the length of board 16. Other board cross sectional configurations can be provided such as with cylindrical shaped longitudinally extending chambers. Additionally, a board with a solid material profile could be employed (i.e. a board in which the hollow chambers are not present, but having generally the same outer dimensions).

The dimensions of board 16 may be the same as conventional boards of lumber. Preferably, board 16 will be configured as nominal 2×3; 2×4; 2×6; 2×8; 2×10; or 2×12 boards, and have lengths which may vary depending on the size of the decking assembly or other application. Additionally, the preferable number of ribs 20 per board 16 is five. Of course, these specifications are merely examples of possible embodiments and many variations are possible.

Preferably boards 16 have coefficients of thermal expansion of greater than 1 m/m/degrees celsius×10 minus 5 and more preferably have coefficients of thermal expansion of greater than 5 m/m/degrees celsius×10 minus 5.

Also as shown in FIG. 2, extending from the sides of each board 16, proximate the edges of each side portions 22 a and 22 b and outer ribs 20 a, 20 b are angled lips 23 a and 23 b, respectively. As illustrated, the top flat surface 22 a has downwardly angled lips 23 a extending from either side, and the bottom flat surface 22 b has upwardly angled lips 23 b extending from either side. The lips 23 a and 23 b preferably extend upward and downward at an angle of about 10 degrees from the horizontal plane. Preferably, the angled lips 23 a and 23 b of the flat side portions 22 a and 22 b extend outward proximate an outermost rib 20 a distance of preferably approximately 0.8 cm. However, as a person skilled in art will appreciate, that such distance and angle may be increased or decreased. Advantageously, angled lips 23 a and 23 b extend from the left and right of top and bottom surfaces 22 a and 22 b, boards 16 and are symmetrical about vertical and horizontal planes through its center. Opposed angled lips 23 a and 23 b form generally dovetailed channels 29, as illustrated. As will become apparent, lips 23 a and 23 b need not extend outward linearly but could be curved or have another shape.

FIGS. 3A, 3B and 3C illustrate, in perspective and cross-sectional views, an exemplary hold-down clip 24. Hold-down clip 24 includes a top portion 25 with a longitudinally extending tab portion 31. Tab portion 31 can be used to hold the clip when installing the clip as described below. Extending down from top portion 25 of hold-down clip 24 are two downwardly extending outer tabs 26 defining a medial region 27 there between. Extending down further than the outer tabs 26, parallel to and equidistant to both outer tabs 26 in region 27 is a spacer tab 28. Thus, hold-down clip 24 is generally T-shaped in cross-section, as best illustrated in FIG. 3B. Spacer tab 28 and each outer tab 26 define a channel 34 a and 34 b in region 27 extending along the length of clip 24. Clip 24 is preferably made of a suitable plastic such as polypropylene and may be formed by conventional methods such as by injection or extrusion molding. Clip 24 could be formed of any other suitable material including a metal such as aluminum, steel or a metal alloy. However, it is preferred that the material from which the clip is made, does not, when the clip is attached to the lips 23 a, 23 b and to the underlying substructure such as joist 14, prevent the board lips 23 a, 23 b from some frictional sliding movement longitudinally. Such movement will be desirable when the board is subjected to thermal expansion and contraction due to changes in temperature, typically caused by changes in the ambient temperature. In a case where the board lips 23 a, 23 b can not slide longitudinally in the clip in relation to outer tabs 26 during temperature changes, sufficient to allow the change in length, then the clips can be subjected to significant loading which might cause them to be come disengaged from attachment to the substructure and/or fail.

Hold-down clip 24 optionally includes a pre-formed bore 30, extending from the center of top portion 25. Bore 30 is sufficiently large to allow a fastener, preferably such as a nail or screw to pass from the center of the top of clip 24 down through the center of the spacer tab 28. Two small solid disks 32 formed as a result of the injection molding process forming spacer tab 28, protrude from the bottom of spacer tab 28, and are located on either side of the hole on the bottom surface of the spacer tab 28.

A screwdriver bit 36 which has its operative end extending a distance preferably at least the distance from the top outer edge of the angled edge 23 a of flat surface 22 a of board 16 to the top inner edge of the angled edge 23 b of flat surface 22 b of board 16, and most preferably a distance greater than the thickness of board 16. Bit 36 has a shaft that is sufficiently thin to allow the adjustment of a screw positioned between two boards 16 while permitting a minimum separation distance between the boards 16. Thus, preferably, the diameter of screwdriver bit 36 will be less than the thickness of spacer tab 28. Screwdriver bit 36 may be a Robertson, Philips, or slotted fit, complementary to screws that may be used to fasten the boards to the substructure 11.

Other types of board attachment mechanisms could also be employed, particularly those which permit the longitudinal frictional sliding movement of the board.

The construction of a decking assembly as illustrated in FIG. 1 using example hold down clip 24 and boards 16 may be better appreciated with reference to FIGS. 4A and 4B. Specifically, FIGS. 4A and 4B illustrate cross-sectional views of a hold-down clip 24 positioned between two boards 16. Boards 16 are placed in a side-by-side relationship on substructure 11, with two lips 23 a of adjacent boards facing each other. As illustrated in FIG. 4A, hold-down clip 24 is placed above one of joists 14 and between two boards 16 such that the angled lip 23 b of the bottom flat surface 22 b of one board 16 is fit within the first groove 34 a of hold-down clip 24. The angled lip 23 b of the bottom flat surface 22 b of another board 16 is fit within the second groove 34 b of hold-down clip 24. Hold-down clip 24 may be fastened to substructure 11 using a conventional fastener such as a nail, screw, staple or the like. Most preferably a screw, such as screw 38 are used.

Screw 38 is positioned in the top hole 30 of hold-down clip 24 and is turned by a screw driver, preferably fitted with screwdriver bit 36 so that screw 38 is engaged by the complementary bit 36 and driven through the hold-down clip 24 into the joist 14, causing a downward force to be exerted on hold-down clip 24. The downward force on hold-down clip 24 acting upon the angled edges 23 b of flat surfaces 22 b causes a camming force to be exerted on each board 16 in a generally horizontal direction, orthogonal to the downward force, and towards hold-down clip 24 as illustrated by arrow P in FIG. 4B. This, in turn, pulls two adjacent boards close together. Conveniently, the diameter of screwdriver bit 36 is narrower than an extending center spacing tab 28 and is sufficiently narrow to allow the screwdriver bit 36 to fit between adjacent boards as they are pulled together. Spacer tab 28 of the hold-down clip 24 conveniently limits the spacing between adjacent boards. Moreover, spacer tab 28 provides an upwardly directed supporting force, opposite to the downward force of screw 38. Alternatively, spacer tab 28 could be eliminated thereby allowing a screw such as screw 38 to act as a spacer between adjacent boards 16.

The combination of the cam force and the downward force causes a strong union between each board 16 and the sub-structure, as well as between each board 16 and each adjacent board 16, resulting in an improved deck function. Moreover, hold down clips 24 spaced along the length of the boards may cause adjacent boards to be equally and evenly spaced and parallel, eliminating the need measure or mark the position of boards 16, as they are being assembled. Preferably, several clips identical to hold-down clips 24 are spaced lengthwise to coincide with the joist spacing.

Advantageously, hold-down clips 24 need not be fixed from the top surface of boards 16, nor through any surface of boards 16. Each hold-down clip 24 is economical to produce, unobtrusive, and results in an aesthetically pleasing deck.

As boards 16 are symmetrical, downwardly extending lips 23 a will be adjacent to each other. So arranged, these facilitate water run-off from an assembled decking assembly 10, and additionally prevent uneven board edges that may cause tripping or interfere with snow removal.

As should now be appreciated, if a decking assembly so assembled needs to be disassembled, fasteners may be removed from hold-down clips 24. Boards 16 remain undamaged by any such disassembly. Moreover, as the boards are symmetrical, any board having a damaged or discolored face may easily be reversed, by loosening the associated fasteners keeping the board in place, and turning the board upside down, and thus reversing the board. Similarly, severely damaged boards may be replaced, one by one, as required. This, in turn, may significantly extend the useful life of any such decking assembly.

The deck assembly 10 as shown in FIG. 1 is shown with the ends of boards 16 substantially aligned with the plane of the outer face surfaces of end joists 14 a, 14 b. However, some circumstances, such as where a deck assembly is subject to significant changes in ambient temperature, the ends of the boards 16 will not remain is such alignment. This does not provide for an aesthetically pleasing result and may provide some functional drawbacks such as boards pushing out and dislodging a facia or other board or trim member, or possibly having a board travelling out of position or sliding off a joist member. Additionally, as not all boards may expand or contract the same amount, non-uniform changes in length can result in undesirable effects such as for example uneven board ends.

Accordingly, with reference to FIGS. 5-11, an edge board member 40 is illustrated. Edge board 40 may be made from the same material as boards 16 and colored either the same color or a different color for contrast. Edge board 40 may be made in the same way as board 16 by an extrusion or pultrusion process. However, edge board can be formed from other materials and using other known manufacturing techniques, including being made from regular lumber, suitably cut to shape to provide an open channel 44 with a suitable opening 54, as described below.

Board 40 as illustrated, is configured with longitudinally extending webs including a front, a rear, side wall portion 46 positioned opposite a front, front side wall portion 48. Interconnecting web portions 53 and 56 provide an enclosed longitudinally extending channel 42. Channel 42 does not have to be square or rectangular in cross section. Indeed, if made from lumber, a hollow channel 42 need not be present at all.

An open, longitudinally extending channel 44 is formed by an upstanding rear wall portion 55 that extends from wall portion 46 and transverse webs 56 and 50. An opening into channel 44 is provided between the ends of webs 50 and 56. The upper, outward facing surface of web portion 50 has an end portion 52 that is wedge shaped, tapering to a narrow tip. This provides a graduated threshold feature which reduces the tripping hazard when installed. Angle alpha may in some embodiments in the range of 15-20 degrees and most preferably about 17.5 degrees for a board that has an outer width of about 1.5 inches. Surface 52 could also in other embodiments be arcuate shaped with the surface being oriented concave downwards.

The use of edge board 40 is shown in FIG. 12 as part of a deck assembly similar to assembly 10 in FIG. 1. Board 16 can be initially cut and/or placed when the deck is assembled with the end portion 16 a received through opening 54 and extending partly transversely into channel 44. Board 16 can be held in position on joists including joist 14 b, as described above.

Edge board 40 is shown in FIG. 12 mounted to joist 14 b with a screw or nail 138; other attachment mechanisms could be used. Apertures may be drilled through outer side portion 46 and inner side portion 48 to permit a screw 138 to be affixed inside channel 42 into joist 14 b. Once screw 138 is affixed in place, an insert plug 136 can be inserted into the aperture through wall 46. Plug 136 can be made of a suitable material such as a plastic material like high-density polyethylene (HDPE) or polypropylene.

Edge board 40 has its outer rear face 48 a mounted flush against the face of the joist 14 b. Thus, the end 16 a is positioned into channel. As shown in FIG. 12, the edge board can be configured so there is a longitudinally extending gap between the lower surface 16 b of board 16 and the upper inside surface of web 56 (FIG. 5). A gap can also be provided between the upper surface of the deck board end, and the inside upper surface of web 50, which may be narrower than the gap at the lower surface of the deck board. These gaps allow for some dimensional increase in the depth of the deck board.

As shown is FIG. 12, the end 16 a of the board 16 can expand longitudinally from the position shown in solid lines, to the position shown in broken lines, such as when there is an increase in temperature of the board. It is preferred that the position shown in solid lines be the limit of the contraction of the board out of cavity 44.

For appearance purposes, as shown in FIG. 12, a longitudinally extending skirting board 150 can also be secured to joist 14 b with screws 138 and covers 136, in a manner similar to that described above. Skirting board 150 can be made from the same material as deck board 16 and edge board 40, and formed in the same manner as board 16.

In an example embodiment, joist 14 is a nominal 2×8 piece of regular lumber. Edge board 40 is configured with the same outer dimensions as a 2×4 inch piece of lumber, and skirting board 150 is configured with the same outer dimensions as a 1×6 piece of regular lumber.

With reference to FIG. 13, a decking assembly 110 is shown which employs a plurality of deck boards 116 a, 116 b (like boards 16) in conjunction with edge boards 140 a, 140 b and 140 c (like edge boards 40). A first deck span 160 is provided by boards 116 a (only two of which are shown, but can involve multiple boards as shown in FIG. 1). Likewise a second deck span 162 is shown provided by boards 116 b.

Boards 116 a are supported by and attached to joists 114 e-g including outer end joists 114 e and 114 g. A first edge board 140 a is mounted to joist 114 e. Boards 116 a have first end portions received in openings 154 of the edge board 140 e, as described above. Screws 138 pass through opposite end portions of boards 116 a pass into joist 114 g to pin these end portions to the joist 114 g. In this manner, any thermal expansion or contraction will be forced to occur at the first end portions, which are covered by edge board 140 e.

Boards 116 b are supported by joists 114 h, 114 i and 114 j in a similar manner. An edge board 140 d is shown mounted to joist 114 h. Boards 116 b have first end portions received in openings 144 of the edge board 140 d, also as described above. Screws 138 pass through opposite end portions of boards 116 b and pass into joist 114 h to pin these end portions to the joist 114 h. In this manner, any thermal expansion or contraction will be forced to occur at the first end portions of boards 116 b, which are covered by edge board 140 d. The boards 116 a, 116 b are secured to the other joists 114 e, 114 f, and 114 i, 114 j, respectively using clips 124 which can be like clips 24.

Positioned between joists 114 g and 114 h, can be a transversely extending, additional breaker board member 141 which can be made from any suitable material such as for example regular lumber or be a NFTPC channel member similar to the board member shown in FIG. 2, but without lips. The breaker board member 141 can be nailed or screwed to joists 114 g, 114 h, and its upper surface bridges the gap between the adjacent ends of deck boards 116 a, 116 b. Breaker board 141 can be supported by a support member 141. The support member 141 can be a nominal 2×4 piece of lumber or other suitable member, and is affixed such as by screws of nails to joists 114 g and 114 h. In another embodiment, the breaker support member could be eliminated and the ends of boards 116 a and 116 b be abutted directly adjacent each other.

A ledger board or rim joist 112 (which may be another piece of lumber like joists 114) is shown in shadow outline, and may be mounted to the ends of joists 114 e-j in a known manner.

One way of assembling deck assembly 110 is as follows. First the substructure is formed which includes joists 114 e-j are mounted in position, typically being attached to a header like board 112, and may be supported by beams and structural support posts (not shown). Thereafter, the support member 241 affixed such as by screws of nails to joists 214 g and 214 h. Next, breaker board member 141 can be installed between joists 114 g and 114 h, supported by support member 141. Next the deck boards 116 a and 116 b are mounted to the joists using screws like the screws 238 and clips 124. The outer ends of deck boards 116 a and 116 b can then be appropriately cut off to make the ends even. The cutoff position on the boards will be selected depending upon the ambient temperature. If the ambient temperature is relatively warm, an overhang of 1-2 cm can be left beyond the outer edge surface plane of outer joists 114 e and 114 j.

By way of example only, for boards 116 a, 116 b that are up to a maximum of 20 feet long, the amount of intrusion into the channel 144 that should be provided for when cutting of the ends of the boards can be extracted or extrapolated from the following chart. For given ambient installation temperatures, and for XTENDEX deck boards manufactured by Carney Timber Company, made from rice hulks, a resin of High Density Polyethylene, combined with certain functional additives such as pigments, lubricants, coupling agents, UV stabilizers, the intrusion allowed in to the channel can be extracted/extrapolated as follows: Ambient Temperature Intrusion 35 degrees F. 0.25 inches 75 degrees F. 0.50 inches 110 degrees F.  0.75 inches

Thereafter, edge boards 140 a and 140 d are mounted to the joists 114 e and 114 j respectively, with the ends of boards 116 a and 116 b being received with sliding transverse movement of the edge boards 140 a into their open channels 144. Screws like screws 138 can then be used to hold the edge boards 140 a, 140 d in position on the joists 114 e and 114 j, as described above.

With reference to FIG. 14, a deck assembly 210 is shown that employs a plurality of deck boards 216 a, 216 b (like boards 116 as described above) in conjunction with edge boards 240 a, 240 b, 240 c, 240 d and 240 e (like edge boards 40). The assembly 210 includes mounting clips 224 (like mounting clips 24) securing boards 216 a, and 216 b to joists 214. A first deck span 260 is provided by boards 216 a (only two of which are shown, but would typically involve multiple boards as shown in FIG. 1). Likewise a second deck span 262 is shown provided by boards 1216 b.

Boards 216 a are supported by and mounted with clips 224 to joists including end joists 214 e and 214 g, as shown. A first edge board 240 a is shown mounted to joist 214 e and a second edge board 240 b is mounted to joist 214 g. Boards 216 a have their end portions received in channel openings of the edge boards 240 a, 240 b, in a manner like that described above.

Likewise, boards 216 b are supported by and mounted with clips 224 on joists including end joists 214 h and 214 j shown. A third edge board 240 c is shown mounted to joist 214 h and a fourth edge board 240 d is mounted to joist 214 j. Boards 216 b have their end portions received in channel openings of the respective edge boards, as described above.

A header board 112 (which may be another piece of lumber like joists 14 e-h and not shown in this Figure), and may be mounted to the ends of joists 214 e-j in a known manner.

Edge boards 240 b and 240 c are positioned in back to back relation as shown, and can be supported by a support member 241. The support member 241 can be a nominal 2×4 piece of lumber or other suitable member, and is affixed such as by screws of nails to joists 214 g and 214 h. The back to back positioning of medial edge boards 240 b and 240 c provides for a smooth transition zone on the deck surface between the two spans 260 and 262. Although there is a raised portion resulting from the upper web portions of edge boards 240 b and 240 c, the sloped surface portions reduce the potential tripping problems associated therewith. Likewise the sloped surface portions of edge boards 240 a and 240 b reduce the potential tripping problems at edges of the deck spans 260 and 262.

As shown in FIGS. 14 and 15, an additional edge board member 240 e (like member 40) can be provided in a longitudinal direction and can have the side portions of members 216 a, 216 b received into the open channels of member 240 e. Mitre joints can be provided where the edge boards meet at their ends. The side edge of board 216 a can also be pinned to the underlying ledger board or rim joist, as can edge board 240 e, by use of screws 238 sealed with caps 236.

It will be appreciated that edge boards like boards 40 can be provided around all edges of a deck.

One way of assembling deck assembly 210 is as follows. First the substructure is formed which includes joists 214 e-j are mounted in position, typically being attached to a header like board 112, and may be supported by beams and structural support posts (not shown). Next, support member 241 can be installed between joists 214 g and 214 h. Next the deck boards 216 a and 216 b can be inserted into the open channels of edge boards 240 b, 240 c respectively and are mounted to the supporting joists using screws like the screws 238 and clips 124. Screws 238 are used to pin the deckboards medially along their length so that the boards will expand/contract substantially the same amount in each of the channels of the edge boards that cover their ends. The opposite ends of deck boards 216 a and 216 b can then be appropriately cut off to make the ends even. The cutoff position and the insertion position of the opposite ends of the boards into the channels of edge board members 240 b, 240 c, can be selected dependent upon the ambient temperature and the length of the board, in a manner similar to that described above in relation to FIG. 13. The assembly can be configured so that any change in length of each board 216 a, 216 b, due to thermal changes or otherwise, will be forced outward from the position of attachment to joists 214. Thus, if a joist 214 is chosen for attachment with screws 238 which is in the proximity of the middle of the span, then any expansion/contraction of the boards 216 a, 216 b will be equally divided between the two edge boards. In other words, the expansion/contraction of boards 216 a, will occur equally into and out of edge boards 240 a and 240 b. Likewise, the expansion/contraction of boards 216 b, will occur equally into and out of edge boards 240 c and 240 d.

Thereafter, edge boards 240 a and 240 d are mounted to the joists 214 e and 214 j respectively, with the ends of boards 216 a and 216 b being received with sliding transverse movement of the edge boards 240 a into their open channels. Screws like screws 238 can then be used to hold the edge boards 240 a, 240 d in position on the joists 214 e and 214 j, as described above.

Thereafter edge board 240 e can be secured to a header board with the sides of boards 216 a, 216 b being received in the channels.

The positioning of where the board is fixed relative to the underlying substructure, can be adjusted depending upon the particular application or situation.

Although edge boards 40 have been depicted for use with deck boards in a decking assembly, they could also be used in other applications, where there is concern for thermal expansion of boards. For example, boards susceptible to expansion and contraction might be employed on siding, and a structure could be employed to utilize edge boards. In such a case, the siding members would typically, but not necessarily, run horizontally, and the edge board members could be employed vertically at the ends of the run on a wall.

The above described embodiments, are intended to be illustrative only and in no way limiting. The described embodiments of carrying out the invention, are susceptible to modification of form, size, arrangement of parts, and details of operation. The invention, rather, is intended to encompass all such modification within its scope, as defined by the claims. 

1. An edge member comprising: (a) an enclosed lower channel defined by lower channel wall portions; (b) an upstanding wall portion extending from said lower channel wall portions, said upper wall portion defining an open channel and providing an opening into said open channel.
 2. An edge member as claimed in claim 1 wherein said upstanding wall portion comprises a vertically upstanding wall portion and a transverse web portion integrally formed at an upper edge of said upstanding wall portion.
 3. An edge member as claimed in claim 2 wherein said opening is defined between an upper web portion of said lower channel wall portions and said transverse web portion.
 4. An edge member as claimed in claim 2 wherein said transverse web portion has at least an end portion that is configured with an outer surface that is angled to narrow towards said end of said transverse web portion, to provide a wedge shaped outer surface.
 5. An assembly comprising: (a) a supporting substructure; (b) at least one longitudinally extending board member supported on said substructure, said board member having an end portion; (c) an edge member mounted proximate said end portion of said board member, said edge member comprising: (i) a lower portion configured for attachment to said substructure; (ii) an upstanding wall portion extending from said lower portion, said upper wall portion defining an open channel and providing an opening into said open channel; said edge member being attached to said substructure and said end portion of said board member being received through said opening of said edge member into said open channel, wherein said channel can accommodate longitudinal expansion and contraction of said board member such that said end portion remains substantially within said open channel of said edge member.
 6. An assembly as claimed in claim 5 where in said at least one longitudinally extending board member comprises a plurality of board members arranged in side by side relation and supported on said substructure, said board members each having end portions received in side by side relation in said open channel.
 7. An assembly as claimed in claim 6 wherein said lower portion of said edge member comprises an enclosed lower channel defined by lower channel wall portions.
 8. An assembly as claimed in claim 7 wherein said upstanding wall portion of said edge member comprises a vertically upstanding wall portion and a transverse web portion integrally formed at an upper edge of said upstanding wall portion and wherein said opening of said edge member is defined between said an upper web portion of said lower channel wall portions and said transverse web portion.
 9. An assembly as claimed in claim 8 wherein said transverse web portion has at least an end portion that is configured with an outer surface that is angled towards said end of said transverse web portion, to provide a wedge shaped outer surface.
 10. An assembly as claimed in claim 6 wherein said board members are made of a material having a thermal coefficient of expansion of greater than 1 m/m/degrees celsius×10 minus
 5. 11. An assembly as claimed in claim 10 wherein said board members are made of a material having a thermal coefficient of expansion less than 5 m/m/degrees celsius×10 minus
 5. 12. An assembly as claimed in claim 6 wherein said substructure comprises a plurality of spaced joist members oriented generally transversely to said board members.
 13. An assembly as claimed in claim 12 wherein said board members are mounted to said joist members with at least one clip member, said clip members permitting longitudinal expansion and contraction of said board members.
 14. An assembly as claimed in claim 13 wherein said board members have a side from which a first lip outwardly extends, said first lip having an upper ramp surface extending upwardly away from said side of said first board and wherein said clip comprises a top portion; a downwardly extending tab extending downwardly from said top portion, said downwardly extending tab pressing on said ramp surface of said first lip of said board member securing said first board member to said substructure.
 15. An assembly as claimed in claim 13 wherein said board members comprise first and second board members, each of said board members having a side from which a first lip outwardly extends, said first lip having an upper ramp surface extending upwardly away from said side of said first board, said first board member and said second board member extending on said supporting substructure with said first lip of said first board member and said first lip of said second board member each extending adjacent to each other; said clip comprising a top portion; two downwardly extending tabs extending downwardly from said top portion defining a medial region between said downwardly extending tabs, said downwardly extending tabs pressing on said ramp surface of said first lip of said first board member and said ramp surface of said first lip of said second board member, thereby pulling said first and second board members inwardly toward said medial region to secure said first and second board members to said substructure.
 16. An assembly as claimed in claim 12 wherein said clip is formed from one of plastic, steel and aluminum.
 17. An assembly as claimed in claim 14 wherein said board members are made from a reinforced fiber plastic composite.
 18. As an assembly as claimed in claim 17 wherein said board members are made from a natural fiber thermoplastic composite material.
 19. An assembly as claimed in claim 15 wherein said clips are formed from one of plastic, steel and aluminum.
 20. An assembly as claimed in claim 18 wherein said edge board members are made from a natural fiber thermoplastic composite material.
 21. An assembly as claimed in claim 5 wherein said end portion of said board member is a first end portion and said board member has a second end portion at an opposite longitudinal end to said first end portion; said assembly further comprising as second edge member mounted proximate said second end portion of said board member, said second edge member comprising: (i) lower portion configured for attachment to said substructure; (ii) an upstanding wall portion extending from said lower portion, said upper wall portion defining an open channel and providing an opening into said open channel; said second edge member being attached to said substructure and said second end portion of said board member being received through said opening of said second edge member into said second open channel, wherein said channels of said first and second edge members co-operate to accommodate longitudinal expansion and contraction of said board member such that said end portions remain substantially in said open channel of said edge member.
 22. An assembly as claimed in claim 21 wherein said board member is permanently affixed in a longitudinal direction at a medial position to said substructure, such that said longitudinal expansion and contraction of said board member occurs in said open channels of both said first and second edge members.
 23. An assembly as claimed in claim 21 wherein said board member is permanently affixed in a longitudinal direction at a medial position to said substructure, such that said longitudinal expansion and contraction of said board member occurs in said open channels of both said first and second edge members.
 24. An assembly as claimed in claim 6 wherein said plurality of board members comprises a first set of board members and said assembly further comprising a second set of board members comprising a plurality of board members; said board members of said second set of board members each having first ends and second ends at an opposite longitudinal end to said first end portion; said assembly further comprising a second edge member mounted proximate said second end portion of each said board member of said second set of board members, said second edge member comprising: (i) a lower portion configured for attachment to said substructure; (ii) an upstanding wall portion extending from said lower portion, said upper wall portion defining an open channel and providing an opening into said open channel; said second edge member being attached to said substructure in an opposite direction to said second edge member, but in proximate relation thereto, and said first end portion of said board members of said second set being received through said opening of said second edge member into said open channel of said second edge member, wherein said channel of said second edge member co-operates to accommodate longitudinal expansion and contraction of said board member such that said end portions remain substantially in said open channel of said first and second edge members.
 25. An assembly as claimed in claim 21 wherein said board member has a longitudinally extending side portion, and wherein said assembly further comprises a third edge member that comprises: (i) a lower portion configured for attachment to said substructure; (ii) an upstanding wall portion extending from said lower portion, said upper wall portion defining a third open channel and providing an opening into said third open channel; said third edge member being attached to said substructure and said side edge portion of said board member being received through said opening of said third edge member into said third open channel, wherein said channel of said third edge member accommodates transverse expansion and contraction of said edge member such that said side edge portion remains substantially in said open channel of said third edge member.
 26. An assembly as claimed in claim 5 wherein said end portion of said board member is a first end portion and said board member has a second end portion at an opposite longitudinal end to said first end portion, said second end portion being fixedly secured at an attachment location to said substructure proximate said second end portion, to resist substantial longitudinal movement of said second end portion relative to said substructure.
 27. An assembly as claimed in claim 26 wherein said board member is also mounted to said substructure with at least one clip member spaced between said attachment location and said first end portion, said clip members permitting longitudinal expansion and contraction of said board member.
 28. An assembly comprising: (a) a supporting substructure; (b) first and second longitudinally extending board members supported on said substructure, said first and second board members each having an end portion; (d) first and second edge members mounted in back to back relation to each other, said first edge member also mounted proximate said end portion of said first board member, said second edge member also mounted proximate said end portion of said second board member, said first and second edge members each comprising: (i) a lower portion configured for attachment to said substructure; (ii) an upstanding wall portion extending from said lower portion, said upper wall portion defining an open channel and providing an opening into said open channel; said first and second edge members being attached to said substructure, and said end portion of said first board being received through said opening of said edge member into said open channel, said end portion of said second board member being received through said opening of said second edge member into said open channel, wherein said channels can accommodate longitudinal expansion and contraction of said first and second board members such that said end portions remains substantially in said open channels of said edge members.
 29. An assembly as claimed in claim 28 where comprises a first plurality of board members arranged in side by side relation and supported on said substructure, said board members each having end portions received in side by side relation in said open channel of said first board member, and further comprising a second plurality of board members arranged in side by side relation and supported on said substructure, said board members each having end portions received in side by side relation in said open channel of said second board member.
 30. An assembly as claimed in claim 29 wherein said lower portion of each of said edge members comprises an enclosed lower channel defined by lower channel wall portions.
 31. An assembly as claimed in claim 30 wherein said upstanding wall portion of each of said edge members comprises a vertically upstanding wall portion and a transverse web portion integrally formed at an upper edge of said upstanding wall portion and wherein said opening of said edge member is defined between said an upper web portion of said lower channel wall portions and said transverse web portion.
 32. An assembly as claimed in claim 31 wherein said transverse web portion of each of said first and second edge members has at least an end portion that is configured with an outer surface that is angled towards said end of said transverse web portion, to provide a wedge shaped outer surface.
 33. An assembly as claimed in claim 29 wherein said board members are made of a material having a thermal coefficient of expansion of greater than 1 m/m/degrees celsius×10 minus
 5. 34. An assembly as claimed in claim 33 wherein said board members are made of a material having a thermal coefficient of expansion less than 5 m/m/degrees Celsius×10 minus
 5. 35. An assembly as claimed in claim 29 wherein said substructure comprises a plurality of spaced joist members oriented generally transversely to said board members. 